A “creuseur”, or digger, a plastic lantern on his head, readies to enter a copper and cobalt mine in Kawama, Democratic Republic of Congo on June 8, 2016. Cobalt is used in the batteries for electric cars and mobile phones. Working conditions are dangerous, often with no safety equipment or structural support for the tunnels. The diggers say they are paid on average US$2-3/day. (Photo by Michael Robinson Chavez/The Washington Post)

Prostitutes working on 10th Ave in New York, USA on June 29, 1997. (Photo by Jon Naso/NY Daily News Archive via Getty Images)

“The Queen” painted fibreglass by artist John Humphreys is displayed backdropped by other works which feature in this year's Summer Exhibition on it's 250th year at the Royal Academy of Arts in London, Tuesday, June 5, 2018. The Summer Exhibition has been held since 1769, with around 1300 works on display this year and most of them available for purchase. It runs from June 12 until August 19. (Photo by Matt Dunham/AP Photo)

A woman holds broken umbrella as a powerful typhoon hits Osaka, western Japan, Tuesday, September 4, 2018. A powerful typhoon blew through western Japan on Tuesday, causing heavy rain to flood the region's main offshore international airport and high winds to blow a tanker into a connecting bridge, disrupting land and air travel. (Photo by Nobuki Ito/Kyodo News via AP Photo)

Women lie in the sun in Domino Park as high temperatures hit the region in Brooklyn, New York, U.S., August 29, 2018. (Photo by Andrew Kelly/Reuters)

A girl stretches next to a pram on the embankment of the Moskva river in Moscow on October 18, 2018. The European part of Russia enjoys an unusually warm weather for the season with temperatures reaching up to 22 degrees centigrade. (Photo by Mladen Antonov/AFP Photo)

A participant races in the Brompton World Championship in Bern, Switzerland October 21, 2018. (Photo by Stefan Wermuth/Reuters)

Daniel Cheong, a dog behaviorist and trainer, steps over a leash as he walks a pack of dogs in Arlington, Va. on November 13, 2018. (Photo by Ricky Carioti/The Washington Post)